A single-step multicomponent synthesis of a quinoline derivative and the characterization of its cyclodextrin inclusion complex

Abstract

Multicomponent synthesis are convergent reactions in which three or more starting materials react in a single step to form the product. In the discovery and development of new drugs, multicomponent reactions offer several advantages over traditional synthesis: shorter experiment time, less need for laboratory techniques and scalability. Thus, the objective of this work was to perform the multicomponent synthesis of a hexahydroquinoline compound whose pharmacological activity has been described previously. The synthesis product was characterized by spectroscopic techniques such as Fourier transform infrared spectrometry and 1H, 13C and HMQC nuclear magnetic resonance (NMR). The mechanism of the reaction was proposed to include a conjugated Michael addition. Subsequently, inclusion complexes (ICs) at 1:1 and 1:2 stoichiometries were prepared with the appropriate cyclodextrin to increase the aqueous solubility and bioavailability of this molecule. Kneading and lyophilization (LYO) methods were used to prepare the inclusion complexes, which were evaluated by phase solubility and 1H NMR spectroscopy, with LYO at a 1:2 stoichiometry having the best results. The ICs were then characterized by differential scanning calorimetry, near-infrared spectroscopy and in vitro dissolution tests, which verified a slower release of the compound with the potential to improve its biological properties.